One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,4)(3,7,8,6)(9,10,15,12)(11,16,19,20)(13,23,22,17)(14,24,21,18)(25,26,30,28)(27,31,35,33)(29,36,37,32)(34,39,40,38)(1,3,5,8)(2,6,4,7)(9,11)(10,16)(12,20)(13,21)(14,22)(15,19)(17,24)(18,23)(25,26,30,28)(27,33,35,31)(29,32,37,36)(34,39,40,38)(1,4,5,2)(3,7,8,6)(10,12)(11,19)(13,22)(18,24)(25,27)(26,31)(28,33)(29,34)(30,35)(32,38)(36,39)(37,40)(9,12,15,10)(11,20,19,16)(13,23,22,17)(14,24,21,18)(9,13,15,22)(10,17,12,23)(11,21,19,14)(16,24,20,18)(25,28,30,26)(27,31,35,33)(29,36,37,32)(34,38,40,39)(9,14,15,21)(10,18,12,24)(11,22,19,13)(16,23,20,17)(25,29,30,37)(26,32,28,36)(27,34,35,40)(31,38,33,39)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.